A study investigating the perfusion of colorectal anastomoses using fluorescence angiography: results of the FLAG randomized trial

Abstract

Aim Our aim was to evaluate the efficacy of indocyanine green (ICG) fluorescence angiography (FA) in reducing the incidence of anastomotic leakage (AL) following colorectal anastomosis. Method A single-centre randomized trial was undertaken between 2018 and 2019. Those patients who underwent a stapled colorectal anastomosis were randomized 1:1 for ICG FA versus visual clinical assessment of blood perfusion of the anastomosed colon and rectal stump (non-ICG FA group). The primary endpoint was to assess whether ICG FA was associated with a reduction in the incidence of AL. Secondary outcomes were the rate of postoperative complications and change in the level of bowel resection. Results A total of 380 patients undergoing sigmoid and rectal resection were enrolled. After randomization, three patients were excluded. The results of 377 cases were available for analysis; 187 had ICG FA and 190 were in the non-ICG FA group. ICG FA identified impaired blood perfusion of the colon in 36 (19%) cases. An AL (grade A, B or C) developed in 48 patients: 17 (9.1%) in the ICG FA group and 31 (16.3%) in the non-ICG FA group (P = 0.04). ICG FA did not decrease the rate of AL of high anastomoses (9-15 cm from the anal verge), at 1.3% vs 4.6% in the non-ICG FA group (P = 0.37). In contrast, a decrease in AL rate was found for low (4-8 cm) colorectal anastomoses (14.4% in ICG FA vs 25.7% in the non-ICG FA group; P = 0.04). Conclusion ICG FA is associated with a reduction in AL following low anterior resection.

Challenges in the interpretation of colorectal indocyanine green fluorescence angiography – A video vignette

“…Traditional intra‐operative visual perfusion assessment has been shown to be suboptimal [3] and surgeons are looking to indocyanine green (ICG) fluorescence angiography as an adjunct to clinical judgement. A significant body of work demonstrated feasibility of use [4,5] and a recent randomized trial showed positive results [6] however, not all studies have found similarly [7]. Although clinical trials are ongoing, signal sensing and presentation have not been standardized.…”

ICG Fluorescence Imaging in Colorectal Surgery: A Snapshot from the ICRAL Study Group

“…Some phase II trials con rmed the feasibility, low cost and high success rate of this procedure (14-17), reporting a leakage rate (< 3%) lower than expected on the basis of historical series, with particular reference to rectal anastomosis. Some randomized prospective controlled trials are going to be published (18), and some other efforts are nalized to a better understanding of dynamic information of perfusion (19).…”

Indocyanine green fluorescence angiography decreases the risk of colorectal anastomotic leakage: Systematic review and meta-analysis

“…Although most of the publications were retrospective, there were 2 prospective studies 13,26 and 2 randomized controlled trials. 11,12 Among the retrospective studies, a number of authors attempted to perform a matched analysis using propensity-scoring. 23,25,27,28,37 We identified only 1 trial which had ongoing recruitment on clinicaltrials.…”

“…Nine studies evaluated the use of ICG FA in a combination of patients undergoing both colon and rectal surgery. 11e13,23,25,29,32,33,39 Although the majority of studies adopted a laparoscopic approach, some studies included a combination of laparoscopic and open approaches, 11,13,23,25,32 whereas others included robotic-assisted surgery, 13,24,26,31 and 1 evaluated the use of ICG FA in transanal, total mesorectal excision. 35 There was also variability regarding the definition of anastomotic leakage.…”

“…Three meta-analyses have been published which analyze the impact of ICG FA on decreasing anastomotic leak rates, 8e10 incorporating no more than 6 studies into their analyses. From 2019 to the present, 13 more studies have been published, 2 of which were randomized, controlled trials, 11,12 and 1 was a nonrandomized, prospective trial. 13 In view of the large increase in the number of studies evaluating the utility of ICG FA in decreasing the rate of anastomotic leaks, we carried out this study to update the literature with a new, more informative meta-analysis incorporating all the recently published studies.…”